EFIDynoTuning Forum

Hey guys,

Looking for some help/info on a lean tip in I'm having on my 03 Cobra. Have the tune decently sorted (I think?) and did rework LWFM table. Been having pretty bad lean tip in issues, car would stumble/buck/pop/ect on the gear shift, and would stumble and go lean just tipping in on the throttle when driving in gear.

Played with manifold volume a bit, first making changes the wrong way, then realizing it needed to be decreased, not increased.

I cut it in half and was instantly better, seems to be good on the 1-2 shift, but when making the 2-3 it shoots a little leaner, then 3-4 even more leaner, ect. I tried reducing it further, but didn't seem like it made meaningful changes.

I've read some different things about how manifold volume changes are described, when changing manifold volume does it adjust the amount of fuel or just the timing of the fuel?

Am I totally missing something else here? I read an old post about injector lag, but I'm running ID1050's so I would think they are of good quality.

Thanks for any help!

Manifold volume is pump shot its the fuel dumped on on transient, its also the transient removal rate too which gets tricky but isn't as significant.

Read your tune with tunerpro and post it and we can check it out. Usually you get transient issues like that when your injector data is wrong. If your not scaled back below the injector max clip limit then you'll have those inconsistencies every time you hit the injector's actual breakpoint.

I haven't downloaded tunerpro yet, here is a quick snip of injector values- everything is scaled down and I believe under the limit?

impossible to tell from that

did you factor in your deltap modifiers?

decipha,

Thank you for the responses. I appreciate it!!!

deltap was changed in breakpoint, high slope, low slope and offset vs rail pressure. they re all the same as this, and the multiplier is the same 1.0

Pretty sure I went off of ID's data on their site?

I will attach another picture, having issues getting tune into Tunerpro, think it's because of the bank/tune settings on my quarterhose, but I'm unable to change them?

why did you null the deltap ?

When I set up the tune I went of of the ID characterization tables ID has on their site, I just plugged in their info off their spread sheet.

Set up for return fuel, E10 and 50psi base fuel pressure.

You dont have the fuel rail pressure sensor anymore?

FRPS is still installed, have been told this was a good thing to keep?

well righy now its useless.

You need the deltap since you have your fuel rail pres sensor so it compensates if your fuel pumps cant keep up to save the engine instead of blowing it up.

but yeah your under the clip limit so should just need to dial in the maf is all.